Street brush construction



Aug. 28, 1962 P. MARTIN 3,050,753

STREET BRUSH CONSTRUCTION Filed Aug. 22, 1958 2 Sheets-Sheet 1 FIG. I.

INVENTOR Philip Martin ATTORNEYS Aug. 28, 1962 P. MARTIN 3,050,763

STREET BRUSH CONSTRUCTION Filed Aug. 22, 1958 2 Sheets-Sheet 2 FIG. 5.

Soft 1 Medium L Hard INVENTOR Philip Martin ATTORNEY 5 3,050,763 STREET BRUSH C(BNSTRUCTION Philip Martin, North Hollywood, Calif., assignor to United Engineering Manufacturing Co., Covina, Calif. Filed Aug. 22, 1958, Ser. No. 756,559 Claims. (Cl. -197) This invention relates to street brush constructions and more particularly to brushes of the type comprising a plurality of bristle tufts affixed to sectoral body members which are in turn afiixed to a circular supporting member connected to the rotary brush shaft.

Such brush constructions have been known for many years and have been widely used for heavy work, especially in the sweeping of streets. When the bristles are worn, they must be replaced or the brush as a whole discarded in favor of a new brush. Much work has been done toward permitting replacement of the bristle tufts, but such prior art schemes are time-consuming and tedious at best. Instead of attempting to provide a brush having bristles which are easily replaceable, the present invention is directed to the provision of brushes which will outlast any brushes known heretofore and yet which are economical enough to permit the entire brush to be discarded when the bristles are worn out.

Prior brush constructions have employed metal bristles in an efi ort to increase bristle life. With such brushes difficulties have been encountered in fixing the bristles in the body members and in maintaining the bristles so fixed. In one prior scheme, molten solder is poured around and onto the bristle ends to form a glob which will resist the pullin of the bristles from the body member. Unfortunately, the use of solder tends to anneal the bristles in a manner which is difficult to control and which is destructive of the desired bristle hardness characteristics. Also, the relative inflexibility of the arrangement promotes breakage of the bristles at the point where they meet the body member. Moreover, metal bristles (particularly straight bristles) tend to break relatively easily due to fatigue, work-hardness, and corrosion. The result may be loss of one or more bristle tufts.

It is accordingly a principal object of the invention to provide improved brushes which overcome the deficiencies of prior brush constructions, including those specifically set forth above.

A further object of the invention is to provide novel brush constructions which are more economical, longer lasting, and simpler than any comparable construction known heretofore.

Another object of the invention is to provide brushes or" the foregoing type which in addition are flexible, rustproof, and substantially waterproof.

A still further object of the invention is to provide brushes of the foregoing type in which the bristle tufts are secured more firmly and permanently than has heretofore been possible.

Yet another object of the invention is to provide improved biush bristles. V

The foregoing and other objects, features, and advantages of the invention will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, and wherein:

FIGURE 1 is a perspective view of a sectoral body member with its associated bristle tufts;

FIGURE 2 is an enlarged sectional view taken along line 22 of FIGURE 1 in the direction of the arrows;

FIGURE 3 is an enlarged View of a bristle employed in the invention;

FIGURE 4 is a side elevation view of a complete brush formed in accordance with the invention;

tats atent FIGURE 5 is a perspective 'view of a' sectoral body member with its associated bristle tufts in preferred form of the invention;

FIGURE 6 is an enlarged sectional view taken along line 66 of FIGURE 5 in the direction of the arrows;

FIGURE 7 is an enlarged sectional view taken along line 77 of FIGURE 5 in the direction of the arrows; and

FIGURE 8 is a view of a modified form of bristle.

Briefly stated, the brush constructions of the invention comprise a plurality of sectoral body members which are attached to a circular supporting member fixed to the rotary brush shaft. Each of the body members has a plurality of recessed passages which receive tufts of bristles. In one form of the invention the bristles are crimped over at their terminal ends which are disposed radially adjacent the recessed passage ends and overlap the body surface at such ends. -A washer is aligned with each passage and is inserted in each recess so as actually to engage the cn'mped bristle ends. A screw is driven into the center of each tuft expanding the bristles against the washer and passage surfaces and the tufts are sealed into the body members by globs of plastic cement which is caused to flow around, under, and over the washers in their recesses.

In preferred form of the invention the bristles aregenerally U-shaped but have expanded and flattened bight-s which rest in the passage recesses and which, together with wires inserted through the bights, prevent loss of the bristles and bristle tufts. Specific bristle embodiments which resist wear, breakage, and corrosion will also be described.

Referring now to the drawings, FIGURE 1 illustrates a sectoral body member 1% preferably formed of wood of suitable thickness and type. The body member is pro- 'vided with a plurality of bolt holes 12 which permit the sectoral members to be secured in complementary-fashion to a circular supporting member 14 (FIG. 4) which is preferably formed of steel or other metal. Member 14 is Med to the end of the brush shaft 16, and the body members are preferably bolted to supporting member 14 as indicated at 18 by bolts which pass through the bolt holes 12 and are secured by nuts or in threaded bores in the supporting member 14. The number of sectoral body members required to complete the brush construction may vary from four to eight, for example, depending among other things upon the size of the brush.

As shown in FIGURE 1, and more fully in FIGURE 2, each body member is provided with a plurality of bristle tuft receiving passages 20. The lower end of the passages may be flush with the lower surface of the body member, but the upper end of the passages is preferably located within radially enlarged recesses 22. Recesses 22 are large enough to accommodate washers 24 which have bores aligned with the passages 20. In each passage 20 are a plurality of bristles 26 which as a group constitute a tuft. The bristles are formed of circular cross-section steel wire (such as hot rolled No. 240 plow steel cyanide bat-h case hardened) which is cut into lengths, corrugated, as shown at 28in FIGURE 3, and then crimped over at one terminal portion 36 at an angle to the remainder of the bristle. The corrugations make the bristles resiliently flexible, so that they resist permanent bending, and in order to makethe bristles resistant to rust, the Wire is coated with a tough plastic, such as polyethylene, 29, prior to the time it is cut into lengths. The bristles thus formed are inserted in the passages 20 through the washers 2 4, and the crimped portions 39 are directed radially outward on the upper surface of the washers 24. A sufiicient number of bris tles is inserted in each tuft passage to ensure a relatively thick tuft (for clarity, fewer bristles being illustrated), and normally at least as many bristles are inserted as can be 'ertcdbn the bristles: causing them to engage the 'ofthe passages 2G and the washer bores snugly. The enlarged head of the screw urges the crimped portions 30 I snugly against the, upper surface of the Washers.

accommodated around the circumference of the washer. Afterthe bristles have been inserted, a screw 34 is driven into the passage 20 down through the center of the tuft. .The screws. preferably have a relatively coarse thread a may; be -similar tothe expansion screws driven into The diameter of the screws is correlated with the diameter of the passages "20, the. washerf bores, and thethickness and number of lead inserts 'in concrete or tile.

bristles 26 so that a' considerable expansive force is exwalls .In someinstances it may bedesirable to employ even more bristles than can be accommodated around the circumference ofthe washers, and the additional bristles may have their crimped portions overlapping somewhat the 'crimped portions of the outer bristles. In such instances,

: pulled from the sectors to, wires 52 are passed through the vidually Within each recess -44. Alternatively, one wire bights of the bristles in sequence as shown in FIGURES 5.

and 6. These wires are preferably formed of stiff metal materim so as to resist distortion under the forces exerted thereon hythe bristles. If desired, the Wires 52* may be constituted by a plurality of pins 'mserted indi may serve several. recesses .by pas-sing from recess to recess in sequence. place the Wires in mating grooves formed in; the upper surface of the sector, as shown in FIGURES Sand 7,

. so that the wires will notinterfere with the close fit beit may be desirable to lengthen the crimpe'd portions to a ensure a firmer hold of the bristles in'the washers.

After-the insertion of the screws 34, the entire bristle end assembly of each tuft is enveloped ina glob of a suitable plastic cement which is caused to flow around, iunder and over the washers and the associated bristle ends and screw heads. Sufiicient cement may be utilized to fill substantially the entire recesses 22, if desired. When all of the tufts have been assembled with their body in the foregoing manner, the body members are then bolted to. the supporting member 14, and the brush constructionv is complete.

The brush construction described has been found to be very effective in street sweeping. The corrugated round cross-section bristles of steel are very strong, yet sufliciently flexible and resilient to resist breakage. The plastic coating prevents rusting of the bristles. The sealing of the bristle tufts to the wooden body members ren- V don the brush substantially insensitive to moisture. Since fused or molten metal is not employed in the construction of the brush, the original hardness properties of the bristles are not disturbed during manufacture, and

ithas been found that such properties are substantially ,7 maintained during the use of the brush. The brush tuft modified .sector 40' has a plurality of passages 42, the

upper ends of which communicate with radially enlarged recesses 44 as in the previously described embodiment of the invention. The general configuration of the sector including a plurality of the recessed passages and the bolt holes 46 is substantially the same as described above. However, in this embodiment of the invention the bristhis take the form shown in FIGURE7 and are generally U-shaped with legs 48 and a bight portion 50 interconnecting the legs. The legs 48 are preferably corrugated as before. The bight portions 50 of the bristles are enlarged and flattened as shown in FIGURE 7 so as to give each I bristle .a head which is too large to be pulled through the passage inserted 42. Thus when .the legs. of the bristles are round :as shown in FIGURE 5, the maximum dimension of the bight of the bristles is preferably less than the diameter of the recesses so that a plurality of the bristle bights may be accommodated side by side in the recesses'has shown in FIGURE 5. Of course, if enough bristles are packed into a the high-ts of the end bristles in each may be somewhat distorted bythe especially disadvantageous.

in the passages 42, the bights 50 serve to anchorthe bristles on the sectors 40. If the recesses 44 are tween the sectors 40 and the supporting members of the brush to which the sectors are attached by the bolts previously described. If the recesses 44 in any circumferen tial row are'formed as a single rectangular groove-the j additional grooves to accommodate the wires 52 will be unnecessary. V

The conjoint action of the wires 52 andthe enlarged bights 50 of the bristles strongly resists any tendency of the bristles to be pulled through the passages 42.. Moreover, each bristle'has its own enlargedv bight, and each bristle cooperates individually with the wires 52, so that if one. bristle should break,the breakage would notsub stant-ially affect the retention of the tuft as a [whole within the passage 42. The bristles of FIGURES 5 through 7 may also be coated with plastic as previouslydescribed to prevent corrosion. Moreover, the bightendof each bristle tuft may be encased in a glob of.plastic cement 'in the manner previously described so as to make a substantially waterproof construction.

FIGURE 8 illustrates a form of larly'well adapted to use in street brushes. In'this form the bristle has areas of difierent hardness. The bottom of the bristle, that is, the end opposite the'bight, is

.hardened to withstand the stresses of the street cleaning operations, while the bight or top portion of the bristles is made substantially softer and more flexible so that the bristles may give somewhat at the points where the bristles meet the sectoral body members, thereby preventing the bristles from breaking off, as they tendto if they are hard and brittle at such points. An intermediate area of the bristle is of medium hardness, although in practice, the soft area at one end blends gradually into the hard area at the other end with no sharp line of demarcation. K

As will be seen hereinafter, the varying bristle hardness V is obtained through heat treatment of the Wire bristle stock, and to waterproof this type of bristle it is preferred to galvanize the same. The bristles employed in FIG- URES 1 through 7 may also be galvanized, if desired. Moreover, while the bristle of FIGURE 8 is shaped for use inthemanner described with reference to FIGURES 5 through 7, within the broader aspects of the invention the varying hardness bristle may also be shaped like the bristle of FIGURE 3 and in other configurations;

v In accordance with the preferred method of'making the bristle of'FIGURE 8, suitable wire stock such as No. 60

high carbon'steel' is drawn through a galvanizing bath, I which anneals the steel and provides the proper flexibility for what ultimately will become the bight portion ofthe bristles. fThe wire is then cut into suitable lengths, say 26. inches, and the lengths of wire are placed one. con- .veyor in parallel succession. The conveyor passes be tween a pair of elongated ovens, such as gas burner ovens,

and carries along the lengths of wire with their ends, of

approximately "6 inches, extending into the respective ovens and subjected to a temperature of about 500 degrees F. for about 15 minutes. When the wires reach thefar end of the ovens, they are removed. from the conveyor and permitted to cool in air, thereby hardening the ends of the wire lengths to the degree desirable for street contact. After cooling, the wire lengths are bent into the U-shape previously described, the softer center portion of 'In' order further to ensure that the bristles will not be I In this form it maybe desirable tobristle which is particu-l each length becoming the bight of the corresponding bristle.

While preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes can be made without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims. Accordingly, the foregoing embodiments are to be considered illustrative, rather than restrictive of the invention, and those modifications which come within the meaning and range of equivalency of the claims are to be included therein.

I claim:

1. In a brush construction, a body member having a tuft passage therethrough, said tuft passage comprising a relatively wide upper portion and a relatively narrow lower portion with abrupt shoulders therebetween; a bristle tuft comprising a plurality of bristles of generally U-shaped configuration, the bignt of each U-shaped bristle having a flat top substantially normal to the length of the bristle and joined to the two legs of the bristle by inwardly extending portions spaced from said flat top and substantially normal to the length of the bristle, said inwardly extending portions abutting said shoulders and said flat top lying within said relatively wide upper portion of said passage when said bristle is assembled with said body member with its legs extending from the narrow lower portion of said tuft passage, the bights of said bristles being arranged in side-by-side succession in said passage upper portion; said body member having channels intersecting said relatively wide upper portion of said tuft passage; and a wire element extending in said channels and through the spaces in said bights in succession.

2. The invention of claim 1, further characterized in that the two legs of each bristle lie in abutting relation to each other at their junctions with said inwardly extending portions thereof.

3. The invention of claim 2, further characterized in that said channels extend in said body continuously through a plurality of said tuft passages, and in that said wire element extends continuously through the closed spaces in the bights or" said bristles defined by the arrangement thereof as aforesaid, and constitutes means for supporting a multiplicity of said bristles while such are being 6 assembled in said tuft passages by passing their legstherethrough as aforesaid.

4. The invention of ciairn 1, further comprising a glob of plastic cement enveloping said Wire element and big'nt portions of said bristles Within said passage and sealing same to said body member.

5. In a brush construction, a body member having a tuft passage therethrough, said tuft passage comprising a relatively wide upper portion and a relatively narrow lower portion with shoulders therebetween; a bristle tuft comprising a plurality of bristles of generally U-shaped configuration, the bight of each U-shaped bristle being enlarged in a direction substantially normal to the length of the bristle and joined to the two legs of the bristle by inwardly extending portions spaced from said enlarged bight, said inwardly extending portions abutting said shoulders and said enlarged bight lying within said relatively wide upper portion of said passage when said bristle is assembled with said body member with its legs extending from the narrow lower portion of said tuft passage, the bights of said bristles being arranged in side-toside succession in said passage upper portion; said body member having channels intersecting said relatively wide upper portion of said tuft passage; and a wire element extending in said channels and through the spaces in said bights in succession.

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